Tufting method and article



APll 15, 1968 1c. WHITESEL. ETAL 3,37,973

TUFTNG METHOD AND ARTICLE Filed July 7', 1965 2 Sheets-Sheet l JOSEPH o.WHITESEL HENRY D. DAWBARN INVENTORS ATTORNEY April 16, 1968 .1.c.WHITESEL ETAL 3,377,973

TUFTING METHOD AND ARTICLE Filed July 7, 1965 2 Sheets-Sheet 2 INVENTORSATTORNEY JOSEPH C. WHITESEL HENRY D DAWBARN United States Patent O3,377,973 TUFTING METHOD AND ARTICLE Joseph C. Whitesel and Henry D.Dawbarn, Waynesboro, Va., assignors to W. R. Grace & Co., New York,N.Y., a corporation of Connecticut Filed July 7, 1965, Ser. No. 470,0137 Claims. (Cl. 112-265) ABSTRACT OF THE DISCLOSURE A woven primarytufted carpet backing with the yarns comprised of polyolen, land theWarp yarn closely spaced and the warp and till yarns woven the axes ofone of them at an angle of from about 3 to 10 from a right angle to theaxes of the other, and with rows of tufts engaged through said primarybacking and extending diagonally across more than one of the warp orfill yarns and perpendicularly to the other warp or lill yarns, all asfurther described hereafter.

This invention relates to primary backings for tufted pile fabrics,tufted pile fabrics comprising such primary backings, and to methods forpreparing the backings and the tufted pile fabrics.

It is present practice to employ a flat woven burlaptype backingmaterial having yarns composed of jute, sisal, or sometimes paper. Aserious disadvantage of this backing resides in the fact that thebacking fabric is not of uniform thickness nor density. Thischaracteristic is, of course, due in part to the actual intersticesbetween the individual yarns and in part to the wide variation inthickness between individual yarns and varying thicknesses in the sameyarn. As a result, the tufting needles sometimes meet no resistancewhatsoever. At the other extreme, the needles encounter maximumresistance due to the necessity for penetrating a thick yarn or doubleyarns. yIn still other instances the needles seem to push aside theyarns with litle or no penetration of the yarn itself. As a result, therows of pile yarn stitches frequently jump back and forth between thesame longitudinal yarns in the backing thus causing gaps betweenadjacent rows of stitches which include as few as one and sometimes asmany as three yarns of the backing material. This causes grinning anduneven rows of pile. Heretofore it has been found necessary to overcomethis disadvantage by producing tufted pile fabrics with sufficient pilelength so that these irregularities are substantially concealed. Theseirregularities occur both longitudinally and transversely of the fabricsince a relatively thick transverse yarn in the backing causes a lateralgap or irregularity in the stitch spacing which cannot be in any waycontrolled by adjustment of the tufting machine.

Since `the pile projections in a cut pile tufted fabric naturally tendto spread more effectively than in the case of an uncut pile fabric, itis, of course, feasible to tuft a lower cut pile fabric and obtainadequate coverage than is the case with an uncut or loop pile tuftedfabric. The present invention permits the provision of a pile fabrichaving much lower pile projections, particularly in a loop pileconstruction, than has previously been possible and still produce acommercially saleable fabric.

ln view of the above causes of unevenness in a tufted pile fabricparticularly in the case of loop pile or low pile height, it might havebeen assumed that theuse of a uniform sheet material would overcomethese disadvantages. Efforts -to obtain satisfactory results using anon-woven sheet backing material have also proved fruitless because inthis case there did not appear to be sufficient friction or bind on theyarns to permit uniform control of pile height, particularly afterdisengagement with the loop-ers. The precise reasons for unsatisfactoryICC results with sheet material are not yet completely understood. lItis believed that in the case of a sheet material the needle merelypunches holes which do not have sufficient tendency -to re-close or gripthe yarn to provide adequate or at least uniform yarn engagement Ias theneedles are removed.

ln a recent patent (U.S. 3,110,905, issued Nov. 19, 1963 to Travis M.Rhodes) there is disclosed an improved tufted pile fabric comprising .aat woven synthetic plastic backing. For information purposes the entiredisclosure of the said Rhodes patent is hereby incorporated herein byreference thereto.

Some difficulty has been encountered in attempts to commercially applythe teachings of the Rhodes patent. ln particular it has been observedthat tufting of the primary backings disclosed in the said patent(especially such backings woven of relatively flat cross sectionpolypropylene yarns) causes considerable rupturing and shattering of thelill (or weft) yarns. This in -turn greatly reduces the strength of thetufted pile fabric produced. The considerable strength of the yarnsprior to tufting somewhat alleviates this problem. However in manyinstances the strength of the tufted pile fabric product is low enoughto make the product commercially unacceptable. To further complicate theproblem it has also been observed that the appearance of the tufted pilefab-ric product is frequently unsatisfactory in that the pile is uneven.This is caused by tufting needles .actually breaking lill yarn ends sothat tufting stitches pull through and -give Ia product having manyloops.

It is a general object of this invention to alleviate theabove-described difliculties.

It is another object of this invention to provide synthetic plasticprimary backing material adapted for use in producing relatively strongtufted pile fabrics.

Another object of this invention is to provide relatively strong tuftedpile fabric comprising a primary backing of synthetic plastic material.

Yet another object is to provide a method for increasing the fabricstrength of tufted pile fabrics comprising a primary backing ofsynthetic plastic material.

Still .another object of the present invention is to provide ia methodfor increasing the fabric strength and quality of tufted pile fabricscomprising a synthetic plastic primary backing material.

Many other objects, together with the numerous advantages of thisinvention will become apparent to those skilled in the art in View ofthe following more detailed description.

In accordance with the present invention the axes of the yarns in one ofthe pluralities of yarns in woven primary backings adapted for use intufted pile fabrics are at an angle of from about 3 to about 10 degrees(preferably about 7 degrees), from a right angle to the axes of theother of the pluralities of yarns. Preferably the ases of the lill yarnsare at an angle to the axes of the warp yarns, so that the bank oftufting needles in the usual tufting machines (c g., about 1400 needlesin a 12 foot span) will strike at least several different fill yarns ineach reciprocal piercing operation, reducing the incidence of lill yarnshattering and thus increasing the fabric strength of the tufted pilefabric product.

The present invention provides primary backings as Adescribed, tuftedpile fabrics comprising such backings, and methods for making thebackings and tufted pile fabrics. The invention and its many advantageswill be better understood from the following description thereof takenin connection with the accompanying drawings, in which:

FIGURE l is a bottom view, on an enlarged scale, schematicallyillustrating a tufted pile fabric of the present invention;

FIGURE 2 is a cross sectional view taken substantially on the line 2-2of FIGURE 1;

FIGURE 3 is a bottom view like that of FIGURE l schematicallyillustrating several modifications thereof; and

FIGURE 4 is a plan view, on an enlarged scale, schematicallyillustrating a woven primary backing of the present invention.

As seen in FIGURES 1 and 2 one form of tufted pile fabric according tothe present invention is made up of a primary backing comprised of aplurality of closely spaced, relatively flat (i.e., essentiallyrectangular cross section) polyolen warp yarns 2 and a plurality ofclosely spaced, relatively flat polyolefin fill yarns 1; and rows oftufting material 3 piercing the yarns of the primary backing. In theillustrated preferred embodiment the lill yarns '1 are lbiased at anangle of from about 3 to about 10 degrecs (preferably about 7 degrees)to the warp yarns 2. As a result, the tuftng stitches in any single rowperpendicular to the axes of the warp yarns occur in at least severaldifferent till yarns (see FIGURE 2).

FIGURE 3 illustrates possible variations of the construction of FIGURES1 and 2. Thus it is permissible'to originally form ribbons much widerthan the iin-al desired width and to fold these one or more times toprovide U- shaped or Z-shaped cross-sections. The upper portion ofFIGURE 3 illustrates the use of folded U-shaped till yarns 4 withunfolded warp yarns 5. The lower portion of FIGURE 3 illustrates the useof folded U-shaped fill yarns 4 with folded U-shaped warp yarns 6. Thetufting 3 is like that shown in FIGURES 1 and 2. Y In connection withFIGURE 3 it will be understood that folded ribbons will be used as lillyarns or warp yarns or both ll and Warp yarns throughout the primarybacking and that FIGURE 3 is merely an illustration of these variationsas opposed to an illustration of an actual tufted pile fabric.

In FIGURE 4 relatively round monoor multifilament warp yarns 8 are usedwith relatively round monoor multitilament fill yarns 7 to form aprimary backing. As in the other illustrationsthe till yarns are biasedat an angle of from about 3 to about 10 `degrees from a right angle tothe Warp yarns.

Other variations, not illustrated, are also contemplated. Thus it isdeemed within the scope of the present invention to use relatively lintwarp yarns together with relatively round monoor multifilament tillyarns; or vice versa; or to use relatively at foamed polyolen (densities45 to 95 percent of normal density) warp yarns with unfoamed relativelyat ll yarns; or vice versa; or to use relatively at foamed polyolein(density about 45 to about 95 percent of normal density) Warp yarnstogether with relatively round monoor multililament ll yarns; or viceversa in forming the primary backing. These constructional variations inthe individual yarns, per se, do not form a part of the presentinvention. They are fully described and claimed in copending, coassignedU.S. application Serial No. 487,402, filed concurrently herewith in thename of one of the present inventors. The entire disclosure of the saidapplication Serial No. 487,402 is hereby incorporated herein byreference thereto.

The individual yarns in the primary backings and tufted pile fabrics ofthis-invention can be comprised of any polyolen such as polyethylene,polypropylene, copolymers of ethylene and propylene and the like.Preferably the yarns, whether they be relatively flat, relatively round,foamed, unfoamed, folded or unfolded, are comprised of polypropylene.

When the preferred polyoletin (i.e., polypropylene) is used in theembodiment illustrated in FIGURES 1 and 2 the individual relatively atyarns 1 and 2 may have an individual denier of from about 300 to about2000. Preferably individual denieris from about 350 to about 1200 andmost preferably about 400 to about 1100, eg., 1080. These yarns, as isthe usual oase, are oriented during 4 manufacture by stretching fromabout 4 to about 10 (e.g., 5, 51/2 or 6 times) times the length asoriginally extruded or otherwise shaped. The width of the relatively atyarns may range from about 20 to about 110 mils (i.e., 0.020 to 0.110inch) with corresponding thicknesses of from about 6 to 8 mils down toabout 2 or 21/2 mils. A typical relatively at yarn used in theembodiment illustrated is a 1080 denier polypropylene ribbon ofessentially rectangular cross section, about 100 to 105 mils wide and 2to 21/2 mils thick. The following tabulation indicates the variation inmake-up of the primary backing with the varying deniers (relaively flat,unfoamed ribbons in all cases):

A typical preferred woven primary backing of the type illustrated inFIGURES 1 and 2 is made from 1080 denrer polypropylene ribbon as boththe warp yarns and the ll yarns.

v en using round polypropylene monoor multilaments in primary backingslike that illustrated in F-IG- URE 4 the denier of the warp yarns 8 mayrange from about 70 to about 800. Preferably the warp yarns are fromabout 100 to about 600 and most preferably from about 200 to about 500denier, e.g., about 400 denier. The ll yarns 7 on the other hand shouldhave an individual denier of from about 600 to about 1100. Preferablythe denier of the ll yarns should be about 700 to .about 1000 and mostpreferably about 750 to about 900, e.g., 800.

In a typical woven primary backing like that illustrated there would beabout 15 ends per inch of 400 denier polypropylene monoor multiilamentwarp yarns and about 10 or l2 ends per inch of 1000 denier polypropylenemonoor multiiilament fill yarns.

In the constructions described (but not illustrated herein) where atwarp yarns are used with round ll yarns, or vice versa; the sizes,deniers, etc., are substantially in the ranges set forth above.

As mentioned, relatively at yarns of foamed polypropylene having adensity of from yabout 0.4 to about 0.85, more preferably about 0.58 toabout 0.78, may also be used. Most especially preferred are relativelyat foamed polypropylene yarns having a density of from about 0.65 toabout 0.75, e.g., 0.68 or 0.70. Denier of foamed polypropylene ribbonsmay be from about 300 to about 2000, preferably about 350 to about 1200and most preferably from about 400 to about 1100, e.g., 750 or 1000.Typical of such foamed polypropylene ribbons are ones having a densityof 0.68, about 980 denier, 3 mils thick and mils wide; or having adensity of about 0.70,

about 770 denier, about 74 mils wide and about 3 mils thick.

The bias angle between the axes of the respective warp and fill yarns ismost readily accomplished by tentering in the usual manner with slightmodification. Thus on a straight through tenter frame it is merelynecessary to provide a slight difference in the speeds of the parallelgripping mechanisms so that one edge of the backing is pulled at aslightly higher speed than the other edge thus imparting the desiredbias. In similar manner it is possible to use a tenter frame in whichone gripping mechanism is disposed at a slight angle to the othergripping mechanism. Obviously combinations of these two procedures canbe used, as well as other means and modes that will be apparent to thoseskilled in the art.

As mentioned the bias is preferably imparted to the ll yarns and is inthe range of from about 3 to about degrees. Bias angles lower than 3degrees do not provide substantial fabric strength increase. Bias anglesgreater than 10 degrees could be used but provide no substantial furtherbenefits and may result in increased wastage. The preferred bias angleis about 7 degrees.

It has been found most economical and hence preferred to accomplishbiasing at the same time that the primary backing is being tentered andheat set in the usual manner. Heat setting temperatures for primarybackings comprised of polypropylene yarns are from about 270 to about310 Fahrenheit. The preferred heat setting cycle is about 30 seconds ata temperature of about 290 Fahrenheit.

The primary backings of this invention can be woven and tufted inconventional manner with commercially available equipment. Typicaltufting procedures will give about 6 to 10 (e.g., 7) tufts per inch ofll and about 5 to 10 (e.g., 6 or 8) rows of tufting per inch of warp.

Variations and modifications other than those specically illustrated ordescribed will be apparent to those skilled in the art. It is intendedtherefore that the scope of the invention be limited only by the scopeof the appended claims which are to be construed as including allobvious Variations or modifications.

What is claimed is:

1. Method for producing tufted pile fabrics having increased fabricstrength comprising weaving the primary backing with polyolen warp andfill yarn, biasing said warp and till yarns relative to one another atan angle more than 3 degrees prior to tufting; inserting rows of tuftsin said primary back with each row extending diagonally across more thanone of said warp and ll yarns and perpendicular to said other wrap andfill yarns.

2. Method of claim 1 wherein said woven primary backing is tentered,prior to tufting the same, to thereby bias the fill yarns in saidbacking and wherein the rows of tufts are inserted diagonally across thell yarns and perpendicular to the warp yarns.

3. Method of claim 2 wherein said primary backing yarns are biased at anangle of about 7 degrees and said biased primary backing issimultaneously heat set by tentering at a temperature of from about 270to about 310 Fahrenheit.

4. Method of claim 3 wherein said heat setting temperature is about 290Fahrenheit.

5. A tufted pile fabric comprising a woven primary backing, said backingwoven of polyolen yarn with the warp yarns closely spaced and ofsubstantially uniform dimension and the fill yarns of substantiallyuniform dimension with the axes of one of said warp and ll yarns at anangle of from about 3 to about 10 degrees from a right angle to the axesof the other of said yarns; rows of tufts engaged through said primarybacking and extending diagonally across more than one of said warp andll yarns and perpendicular to said other warp and ll yarns.

6. The tufted fabric of claim S wherein the wrap yarns have a relativelyflat cross section and the tufts extend diagonally across the ll yarnsand perpendicular to the warp yarns.

7. The tufted fabric of claim 6 wherein the yarns are comprised ofpolypropylene, the warp yarns have an individual denier of from 400 to1100 and the fill yarns have an individual denier of from about 700 toabout 960 and the primary backing has about l2 fill ends per inch.

References Cited UNITED STATES PATENTS 1,227,426 5/ 1917 Grabau et al.3,106,507 10/1963 Richmond 139-420 X 3,110,905 11/1963 Rhodes 112--4103,237,578 3/1966 Dietz 112-79 3,317,366 5/1967 Dionne 161-70 X JORDANFRANKLIN, Primary Examiner.

I. R. BOLER, Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE -OF CORRECTION Patent No.3,377,975 April 16, 1968 Joseph C. Whtesel et al.

It is certified that error appears in the above identified patent andthat said Letters Patent are hereby corrected as shown below:

Column 5, line 39 and Column 6, line Z1, for "wrap", each occurrenceshould read y warp Signed and sealed this 9th day of September 1969.

(SEAL) Attest:

Edward M. Fletcher, Jr. JR.

Attesting Officer Commissioner of Patents

